Compressor-controlling mechanism



Nov. 6, 1923. 11,473,78

L. J. CLAPP COMPRESSOR CONTROLLING MECHANI SM Original Filed June 15 1920 :To' whom it'mcy concern:

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Application filed June 15, 1920, serial No. 889,197. Renewed January 31, 1828.

Be it known that l, Lewis J. CLArr, a

citizen of the United States, residing at 'Claremont, in the county of Sullivan and State of New Hampshire, have invented certain new and useful Improvements in Compressor-Controlling Mechanisms, of which the following is a full, clear, and exact specification. I

My invention relates to compressor controllmg mechanisms.

An object of my invention is to provide an improved compressor controlling mechanism. Another object of my invention is to provide an improved compressor controlling mechanism Which shall control both the running of the compressor and its condition whether loaded or unloaded. Other objects of my invention will appear in the course of the following specification and claims.

.In the accompanying drawings I have shown for purposes of illustration, one form which: myinvention may assume in practice.

In these drawings,-

Fig. 1 is a side elevation of a. compressor plant embodying my improved controlling mechanism and showing parts broken away to illustrate details of construction. I

Fig. 2 is a central longitudinal vertical section through my improved compressor controlling mechanism proper.

Fig. 3 is a fragmentary detail of the electric control mechanism.

For purposes of illustration I have shown my improved controlling mechanism applied to a compressor which is generally indicated b 1 and which is driven by a motor 2, t e latter being supplied with electric current from mains 3 and 4 under control of a main switch 5. The main switch 5 is controlled by a pilot switch 6 (see Figs. 2 and 3) which is of well known construction and in which the circuit controlled by the switch is opened and closed respectively by the application of pressure to and the removal of pressure from the o erating pin 7. The details of construction 0? this switch are well known and further description is accordingly considered unnecessary. It will be obvious that when the circuit controlled by the switch 6 is' opened the solenoid 8 which operates to cause the closing of the main circuit through the motor will be without current and accordthe motor stopped. The discharge chest9 of the compressor is connected b means of a pipe 10 with a receiver 11 which in turn is connected by way of a pi e 12 with a Judson pilot valve of well linown constrnction, the pilot valve being of that type which upon rise in receiver premure above the desired limit operates to admit a flow of receiver pressure through the pilot valve and, upon a drop of the pressure to a predetermined degree, to cause a closure of the communication opened through the ilot valve and the opening of an exhaust. his pilot valve is designated by 13 and its exaust is indicated at 14, this exhaust being open at such time as the pilot valve is closed. The compressor is rovided with inlet valve mechanism of we 1. known type comprising valve members 15 (of which but one is shown) adapted to be opened by suction within the compressor cylinder and normally yieldingly held closed by a spring 1.6. Cooperating with a stem 17 formed on the valve 15 is a plunger 18 which is adapted to be raised by air transmitted by the pipe 19 and when so raised to open and so maintain, during the continuance of the air pressure supp-1y, the inlet valves 15, thereby permitting the air on opposite sides of the compressor piston to surge back and forth without the further pumping of air into the receiver.

My improved controlling mechanism, which is generally indicated by 20, comprises means for supplying air to the plungers 18 andpreventing escape therefrom prior to the moment when the compressor driving motor 2 has brought the compressor up to speed, and means for controlling the switch 6- whereby the compressor driving ,which is adapted to contact wit the in 7 when the piston is adjacent the. left and end of the Zylinder and thereby cause the opening of e switch 6 and the resultant opening of the main circuit through the motor 2. Located at the right hand end of the cylinder 21 and arranged within a. cylinder closure member 26 is a valve 27 slidably mounted in a chamber 28 and having a pin 29 adapted to be engaged by the piston 22 when the latter is at the right hand end of its travel. When the piston 22 is in right hand position, the valve 27 stands open,

being moved from its seat 30 and air may pass, on opening of valve 13, by way of the port 31 surrounding the stem 29 to the chamber 28 and thence by way of a. pipe 32 through the pipes 19, thus resulting in an opening of the valves 15. The valve 27 is normally closed by a spring 27'.

The operation of the mechanism described is as follows:

Let it be assumed that the compressor 1 is being driven by the motor 2 and that the pressure in the receiver-11 rises above a predetermined height. When this occurs, the pilot valve 13 is operated to close the exhaust 14 in a well known manner and to transmit pressure to the cylinder 21 by way of the connection 33. Prior to this time the valve 27 has been maintained open by the pressure of the piston against the stem 29, but upon movement of the piston 22 to the left, the valve 27 will at once close. Prior to this event, however, pressure will be transmitted between the head of the piston 22 and the member 26 and through port 31, chamber 28, and pipes 32 and 19 to act upon the lower sides of the piston members 18 to open the inlet valves. As soon as the pressure of the piston 22 is removed from the stem 29, the valve 27 closes and entraps the pressure within the pipes 32 and 19 and beneath the plungers 18. lVhen the piston 22 approaches its left hand limit of travel it throws the switch 6, opening the circuit therethrough and so opening the main circuit through the motor 2 causing resultant stopping of the latter. When the pressure Within the receiver 11, due to the use of air therefrom, drops too low, the pilot valve 13 operates to cut 011? the supply of air to the chamber 21 and open communication between the latter and the exhaust port which is preferably of relatively small size. The piston at once begins to move to the right hand end of its cylinder under the influence of the spring 24 and a very slight movement of the piston will permit the closing of the switch 6 .and the resultant starting of the motor. Prior to the time when the piston 22 reaches a. point where it will contact with the member 29, the motor will have brought the compressor up to full speed, and so the exhaust of air beneath the plunger 18 which will take place whenthe opening of the valve 27 by the piston 22 brings the pipes 19 and 32 in communication with the exhaust port 14, will cause a reloading of the around the plungers 18, the valve 27 will be momentarily opened by the pressure within the cylinder 21 and accordingly the pressure beneath the pistons 18 will be maintained sufiicien-t to cause the compressor to remain unloaded.

\Vhile I have in this application specifically described one form which my invention' may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in other forms Without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. The combination with a compressor and a driving motor therefor, of controlling means for said compressor and for said motor comprising a cylinder, a piston therein, a plunger on said piston, means in alinement with said plunger and engageable thereby for controlling said motor, and means coaxially arranged with said piston and controlling the condition of said compressor.

2. The combination with a compressor, a driving motor therefor, and a receiver, of controlling means for said compressor and for said motor comprising a cylinder, a piston therein, means normally disposing said piston in one end of sald cylinder,

means responsive to receiver pressure to supply and exhaust fluid to and from said cylinder, means in alinement with said piston for controlling said motor, and means coaxially arran ed with said piston for controlling the loading of said compressor and controlled by said piston when the. latter is adjacent the end of said cylinder. toward which it is disposed by said second mentioned means.

3. The combination with a compressor, a driving motor therefor, and a receiver, of controlling means for said compressor and for said motor comprising a cylinder, a piston therein, means responsive to receiver pressure to supply and exhaust fluid to and from said cylinder, means in alinementv with said piston for controlling said motor, and means coaxially arranged with and adapted to be controlled by said piston for controlling the loading of said compressor said last mentioned means being disposed at the opposite side of said piston from said motor controlling means.

4:. The combination with a compressor, a driving motor therefor, anda receiver, of controlling means for said eompressora-nd for said motor comprising a cylinder, 8.

rename to receiver piston therein, means responsive fluid from pressure to supply and exhaust said cylinder, means in alinement with said loading and unloading there piston for controlling said motor, and means coaxially arran with said piston and adapted to be impacted thereby for controlling the condition of said compressor, said last mentioned means being disposed at the opposite side of said piston from said motor controlling means.

5. The combination with a compressor, a driving motor therefor, unloading means for said compressor, controlling means for said driving motor, and a receiver, of controllin mechanism for said compressor unloading means and motor controlling means comprising means subjected on one side to the action of a spring, means for subjectin the opposite side of said third mentione means to receiver pressure or to atmospheric pressure depending upon the receiver pressure, and means, on opposite sides of said third mentioned means and controlled. thereby for controlling said unloading and motor controlling means.

6. The combination with a compressor, a driving motor therefor, and a receiver, of controlling means for the compressor and for the motor comprising a cylinder, a piston therein, means responsive to receiver pressure for alternately supplying receiver pressure to said cylinder and exhausting it therefrom, and a valve adapted to be opened by said piston when the latter is at one end of its travel and when so open to permit the flow of fluid premure to or from said compressor controlling means, through said cylinder.

7. The combination with a compressor, a drivin motor therefor, and a receiver, of contro ing means for said compressor and for said motor comprising a'cylinder, a piston therein, means responsive to recelver pressure for supplying fluid pressure to said cylinder or exhaustin it therefrom, means adapted to be actuated by said piston to control said motor, and a valve controlling said compressor controlling means and normally held open by said piston to admit a supply of fluid pressure to said compressor unloading means from said cylinder and to discharge the same therefrom and having means to close it upon movement of said 'piston upon admission of fluid pressure to said cylinder.

8. The combination with a compressor and a driving motor therefor, of controllin means for said compressor and for 'sai motor comprising a stationary member, a movable member therein, and movable elements disposed at opposite sides of said movable member and operable thereby for effecting control respectively of said driving motor and of said compressor.

9. The combination w1th a compressor and a driving motor therefor, of controlling means for said compressor governing the o and for said motor governing the starting and stopping thereof including relatively movable cylinder and piston elements, and means engageable b the opposite ends of the movable one of sai elements respectively controlling loading and unloading and starting and stoppmg of the motor.

of the compressor 10. The combination w th a compressor Y and a driving motor therefor, of controlling means for said compressor verning the loading and unloading thereo and for said motor governing the starting and stoppin thereof including a stationary cylinder an a piston movable therein, and means engageable by opposite ends of said piston respectively controlling the loading and unloading of the compressor and the startmg and stopping of the motor.

11. In a compressor system, a compressor, a driving motor therefor, a oontrol'switch therefor, unloading means for said compressor including a discharge pressure responsive valve, mechanism controlled thereby operative on supply of fluid to unload the compressor and a connection between said valve and mechanism including a one-way check valve opening toward said mechanism, and means controlled by vsaid compressor discharge pressure responsive leadin thereto, and means for controlling said iving means and said loadin unloading means including a cylin er, a piston in said 0 linder, an element adapted to be actuated y said piston to'interrupt the driving of said compressor by said driving means, compressor discharge pressure and responsive means controlling the movements of said piston and controlling the supply and discharge of fluid pressure to said connection to said compressor loading and unloading means, and a supplemental controlling means in said connection mechanically controlled by said piston.

13. In a compressor system comprising a compressor and means for driving the same, means for stopping and starting the compressor in accordance with variations in discharge line pressure and for causin said compressor to be started unloaded an to be loaded when a predetermined speed of drive is reached comprising a member movable in opposite directions when compressor d1s-- charge pressure respectively exceeds and falls below a predetermined amount, means for controlling the compressor driving means adapted to be actuated by said member adjacent one'end of its path of movement, and a valve adapted to be moved to open position and controlling the loading of the compressor arranged to be opened as said member approaches the opposite end of its movement.

14. In a compressor system comprising a compressor and means for driving the same, means for stopping and starting the compressor in accordance with variations in dissaid to be charge line pressure and for causin compressor to be started unloaded an loaded when a predetermined speed of drive\ is reached comprising a member movable in o posite directions when compressor discharge pressure respectively exceeds and falls below a predetermined amount, means for controlling the compressor driving means adapted to be actuated by said member adjacent one end of its path of movement, a valve adapted to be moved to open on one movement thereof,

compressor to be started unloaded and to be loaded when a predetermined speed of drive is reached comprising a member movable in opposite directions when compressor discharge pressure respectively exceeds and falls below a predetermined amount, means including-a switch for con-trolling the compressor driving means adapted'to be actuated by said member adjacent one ond of its path of movement, and a valve adapted to be moved to open position and controlling the loading of the compressor arranged to be opened as said member approaches the opposite end of its movement.

16. In a compressor system comprising a compressor and means for driving the same, means for controlling the driving of said compressor by said driving means, fluid pressure means for loading and unloading said compressor comprising a compressor discharge pressure controlled pilot valve, means movable in opposite directions upon opening and closing of said pilot valve, means for controlling the operation of said motor actuated by said last mentioned means and means including a valve controlling the flow of fluid pressure which controls operation of said unloading means actuated by said fourth mentioned means on opposite movement of the latter.

In testimony whereof I afiix my signature.

' LEWIS J. CLAPP. 

